The statements in this section merely provide background information related to the present disclosure and may or may not constitute prior art.
Many transmission shift pattern features have the ability to hold a lower gear than requested by pattern for a predetermined period of time before shifting. Once the conditions to hold the lower gear are no longer true (e.g. pedal tip-in/power on) then the transmission upshifts to the next pattern gear immediately. Electronically controlled shift point sequencing has been developed to catch these transitions and control the desired gear towards a pattern gear with a smooth transition and in a way that provides consistent performance to the customer.
In order to realize more advantages multi-speed transmissions such as better fuel economy, improved driveability, and shifting smoothness, a proper gear shift strategy being implemented in a transmission control module is of substantial importance.
The transmission mediates between the engine power and the power demand at the wheels by choosing a suitable gear ratio. Under dynamic driving conditions, the transmission is required to shift in order to match the power requirements commanded by the operator. A gear shift decision is also required to be consistent such that vehicle can remain in the next gear for a period of time without deteriorating the acceleration capability. Otherwise, this will result in an unwanted engine lugging and shift busyness of the gear box.
As transmissions get more gear ratios, e.g., 8, 9, 10, or higher multi-speed transmissions, the task of choosing the most appropriate gear to match the current driving conditions become increasingly difficult. Thus, while current strategies for automatically controlling the upshift sequencing of transmissions achieve their intended purpose, there is a desire to have a strategy for controlling the upshift sequencing of high multi-speed transmissions.